You might have noticed that in my posts so far, I have emphasized the importance of scaling the heavier ingredients. Especially when I am baking, I weigh my heavier ingredients EVERY time. Well…not quite EVERY time…let’s stick with ALMOST every time (I’ll cover one exception in an upcoming post). This short post examines WHY that is so important.
In the realm of cooking, the quantity of an ingredient is typically measured-out in one of three ways: (1) by mass or weight (16 ounces of bread flour), (2) by volume (1 cup of unsalted butter), or (3) by count (3 individual fully ripened bananas). Count should be fairly self-explanatory – I want to focus here on the problems that arise trying to bridge measuring by mass and by volume.
Mass refers to the heaviness or weight of something. Volume refers to the amount of space that something occupies (usually as specified by the space inside of a measuring container). Mass is measured on a scale in units like grams, kilograms, ounces, or pounds. Volume is measured using containers in units like teaspoons, tablespoons, cups, pints, quarts, gallons, or liters. Technically and scientifically, measuring by volume is only well defined for liquid ingredients, though in the years before the availability of inexpensive kitchen scales, most recipes for home cooks specified amounts of all ingredients using volumetric measure.
From this history of using various containers to parse ingredients by volume, there emerges a device that, for all intents and purposes, is the father of lies: the measuring cup. Well…not quite ALL intents and purposes…let’s stick with ALMOST all intents and purposes. Here are two such offensive devices from my pantry – both are equally persuasive but misleading: 1 cup = 8 ounces.
HEY HEY HEY! If Pyrex says it’s true, shouldn’t it be true? Well…yes and no. Yes, in that it IS true for water. No, in that it is NOT true for just about everything else.
Life Lesson – With very few exceptions, you should never assume that there is any simple relationship between the volumetric measure of something and its weight. More specifically, for almost every ingredient you will ever cook with, a cup is NOT equal to 8 ounces.
Two examples where you CAN expect agreement.
Example 1 – Water – 1 cup = 8 ounces
Empty 1 cup measure.
1 cup measure – filled to capacity with water.
Example 2 – Butter – 1 cup = 8 ounces (equivalently: 1/2 cup = 4 ounces)
See equivalency in lower left-hand corner of label.
Scaled – and assuming the wrapper weight is insignificant.
However, you don’t have to go very far before the disagreements crop up.
Example 3 – Milk – 1 cup > 8 ounces
Wow – 8.5 ounces.
This result is particularly troubling. Throughout all of my culinary training, I was taught that 1 cup milk = 8 ounces. Even a brief Googling of the weight of 1 cup of milk will lead you believe that is true. My milk jug begs to differ. According to the nutritional information supplied with my whole milk, 1 cup of milk should weigh 241 grams. Since 1 ounce = 28.3495 grams, 1 cup milk = (241 / 28.3495) ounces = 8.5 ounces. Please note that this expectation matches the weight on my scale.
For the milk, the nutritional information provided on my milk jug agreed with my reality – that’s nice. Unfortunately (or fortunately?) I learned that what I had learned to expect, and what much of the internet assumes to be true, is not borne out in fact.
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Next, let me delve into the larger problem that arises when you try to assign weights to volumes of dry ingredients.
I’ll start out with an ingredient that doesn’t seem too controversial – sugar. Let’s see.
Example 4 – Sugar – How Much Does 1/4 Cup of Sugar Weigh?
Here, let’s just examine the expectation versus the reality.
Expectation – Right Off The Bag.
There are 12 teaspoons in 1/4 cup – so let’s multiply the teaspoon weight of the sugar from the bag (4 grams) by 12: 12 x 4 grams = 48 grams. So the expectation should be that 1/4 cup of sugar weighs about 48 grams.
Empty 1/4 cup measure.
1/4 cup of sugar.
Conclusion: The 1/4 cup measure seems pretty far off – my scale suggests that 1/4 cup of sugar weighs 58 grams rather than 48 grams. But if you convert that to a percentage, the volume in my measuring cup is more than 20% above of the expected weight. That’s a lot of variation.
Things don’t get any better when we go from granulated sugar to flour.
Example 5 – Flour – Part 1: Scoop & Sweep – How Much Does 1/4 Cup of Flour Weigh?
Once again, I want to examine the expectation versus the reality. For this example, I measured my flour using the “Scoop & Sweep” method of gathering flour – I scooped-out a heaping measure of flour directly from the bag then used the back of a knife to sweep the flour level with the edge of the measuring cup.
Expectation – Right Off the Bag.
1/4 cup of flour.
Expectation: 30 grams. Reality: 44 grams. WHAT??? Ouch!
Example 6 – Flour – Part 2: Sift & Spoon – How Much Does 1/4 Cup of Flour Weigh?
OK, let me try filling the measuring cup differently. For this example, I measured my flour using the “Sift & Spoon” method of gathering flour – fist, I sifted flour from the bag to aerate the flour, then I gently spooned the sifted flour into my measuring cup. Before I weighed the result, I used the back of a knife to sweep the flour level with the edge of the measuring cup.
Also 1/4 cup of flour.
Expectation: 30 grams. Reality: 36 grams. Still ouch!
Example 7 – Flour – So…How Much Does a Cup of Flour Weigh?
Here comes the REALLY discouraging part. I came across this discrepancy over the last week while I was scouring a ton of recipes for ideas about how to approach making cinnamon rolls using only honey as a sweetener (i.e. no sugar, no brown sugar, no confectioners sugar). I’ll write a post about that whole journey sometime over the next two weeks.
First of all, let’s examine the expectation in greater detail.
Expectation.
From the side of the bag of flour, it suggests that 1/4 cup flour = 30 grams – so 1 cup flour = 4 x 30 grams = 120 grams.
To bring my point home, I want to convert this weight into ounces. Since 1 ounce = 28.3495 grams, 1 cup flour = (120 / 28.3495) ounces = 4.233 ounces.
So 1 cup flour should weigh about 4 1/4 ounces.
Next, let me show you what my reality was. I used the “Scoop & Sweep” method here – no sifting, no spooning.
Oh…good grief!
Expectation: 4.2 ounces. Reality: 5.7 ounces. That’s about a 37% excess.
I repeated this experiment using the “Sift & Spoon” method. This time I got closer:
Expectation: 4.2 ounces. Reality: 4.7 ounces. That’s about a 12% excess.
It would be easy enough to write-off my excessive weights to being a Taurus and, therefore, heavy-handed in everything I do. But it’s not that simple.
Slowly, but surely, many tele-chefs and other respectable cooking establishments are publishing recipes that include both volumetric and weighted measures for ingredients. Having both measures available to us gives us a glimpse into how some professionals identify what a cup of flour weighs.
Example 1 – America’s Test Kitchen – a quick survey of various bread recipes from their website shows they equate 1 cup flour = 5 ounces (somewhere between my “Sift & Spoon” and my “Scoop & Sweep” weights).
Example 2 – Alton Brown – reading through his book “I’m Just Here For More Food” I see that he equates 1 cup flour = 4.75 ounces.
Example 3 – King Arthur Flour – yeah, OK, this one should be a no-brainer. King Arthur Flour sells flour in grocery stores, so it shouldn’t surprise anyone that in their book “King Arthur Flour: The Baker’s Companion” they equate 1 cup flour = 4.25 ounces – which is the expectation value I got off my own sack of their all-purpose flour. Yeah, that’s the side of a bag of King Arthur’s All Purpose Flour in my pictures above – so judging by their book, that’s their story and they’re sticking to it.
Do you see what I’m getting at here? My reality differs from the suggested reality of America’s Test Kitchen which differs from the suggested reality of Alton Brown – and all of our realities differ from the expectation set-forth on the bag of flour.
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There are three takeaways here:
Takeaway 1 – Using volume to measure dry ingredients generates wildly inconsistent results (in terms of weight). Even professionally published results differ on the relationship between volumes and weights!
Takeaway 2 – Weighing dry ingredients means never having to say you’re sorry. Regardless of who is doing the measuring by weight, 16 ounces = 16 ounces. Every time. Scaling dry ingredients generates consistency in results.
Takeaway 3 – Thinking back to the long history of recipes using volumetric measures for all ingredients and knowing that volume measures of dry ingredients can vary wildly, it is truly amazing that the wealth of old recipes were reliable at all. The successes springing from the Pillsbury and Good Housekeeping test-kitchen cookbooks are a testimonial to how robust a lot of recipes can be! I am utterly in awe that many of the recipes worked at all given the certain variety of individual cook experience.
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